Water Rocket Forum

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A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is constructed from thin plastic or other non metallic materials (usually a used plastic soft drink bottle) weighing 1,500 grams or less. The water is forced out by compressed air. It is an example of Newton's third law of motion.

motorcyclepilot wrote:Just finished building, per the very clear instructions. A fun project! Bench test went great! Lights blinked, button pushes did as expected, and the servo motor servo'ed. The only exception is no sound form the speaker. All parts were "OEM" except the battery, a Turnigy 1s 360. Re-checked all solder joints and they look good to me. Put a meter to the speaker and tested from the meter to the pins on the mc socket and continuity was good. Re-flowed those joints, just in case. Not sure if I can apply a test voltage across the speaker pins safely.

Guidance please?

The most obvious problem would be that the speaker is somehow defective. This is assuming that the chip is good and the speaker was installed with the correct polarity. There should be a + mark on it that has to be installed in the right position, but the mark may be on the underside where you cannot see it. The LaunchPad usually comes with a spare chip, so you can swap that out easily because it plugs in a socket to find out if the chip is bad. If the speaker is bad then you're going to have to get another.

motorcyclepilot wrote:Just finished building, per the very clear instructions. A fun project! Bench test went great! Lights blinked, button pushes did as expected, and the servo motor servo'ed. The only exception is no sound form the speaker. All parts were "OEM" except the battery, a Turnigy 1s 360. Re-checked all solder joints and they look good to me. Put a meter to the speaker and tested from the meter to the pins on the mc socket and continuity was good. Re-flowed those joints, just in case. Not sure if I can apply a test voltage across the speaker pins safely.

Guidance please?

The most obvious problem would be that the speaker is somehow defective. This is assuming that the chip is good and the speaker was installed with the correct polarity. There should be a + mark on it that has to be installed in the right position, but the mark may be on the underside where you cannot see it. The LaunchPad usually comes with a spare chip, so you can swap that out easily because it plugs in a socket to find out if the chip is bad. If the speaker is bad then you're going to have to get another.

Hopefully this gives you some things to test.

Good luck!

It turned out to be a broken trace on the board. No continuity between pin 8 on the mc and the xout solder pad. It may have come loose when i was removing the headers. I started by removing the speaker and using a headphone test plug I made to test it with my shop radio. It worked fine. Then used test leads to find out where the signal dropped out. Worked perfectly when connected to the ic pins but not to the pads. Gnd is okay, just xout not working. Now...on to bench testing!

motorcyclepilot wrote:
It turned out to be a broken trace on the board. No continuity between pin 8 on the mc and the xout solder pad. It may have come loose when i was removing the headers. I started by removing the speaker and using a headphone test plug I made to test it with my shop radio. It worked fine. Then used test leads to find out where the signal dropped out. Worked perfectly when connected to the ic pins but not to the pads. Gnd is okay, just xout not working. Now...on to bench testing!

I'm building my own LauchPad Altimeter, but I have a problem about buying connector for Turingy Lipo batteries: buying them from HobbyKing costs 102 dollars because of shipping fee (I live in Italy) and I think it's a bit expensive
I'm searching on e-Bay and Amazon these days with the product key avaliable on HobbyKing (I don't know their name or any other code) website but until now I found nothing... So:

Does anyone know any other website (not Hobby King) selling connectors for Turingy Lipo batteries? Does anyone know their name or their product code?

Thank you to people wich will reply and to everyone developed the altimeter!
(and sorry for my terrible grammar)

Tom

T.Valerio & Soci - Santo Stefano Water Rockets Team

Take a look at our:Facebook page facebook.com/razzi.s.stefano/YouTube channel youtube.com/channel/UCn85UPNv8vw84-irTR4Db7gg

Lost on a tree wrote:I'll try. Phone batteries seem to be too much heavy for small rockets, so I think I'll destroy a very old r/c helicopter to get its battery...

Any small 3.7V battery will work. I actually used one from a toy micro helicopter since I already had the charger to go with it and could buy replacement batteries cheap on ebay. The real challenge was finding the mating connector for this particular battery since it was non-standard. I ended up finding the mating connector for my particular battery pack on ebay but it took a bit of digging.

If it's more readily available to you on ebay, I'd recommend finding any small 100-200mah 1S (3.7V) lipo battery with leads so that you can use whatever mating connector set you have available. Ideally try using a connector set that is a more common connector like JST or something. That with a cheap charger with JST leads and you're ready to go!

Thank you to everyone answered.
Yesterday I found a solution to my problem: I put two pieces of tiny copper electrical cable inside the two holes in the battery, then I fixed them with hot glue. It seems to be enough reliable. You can warm the glue and "put away" the cables when you want. May be this will be useful to somebody.

T.Valerio & Soci - Santo Stefano Water Rockets Team

Take a look at our:Facebook page facebook.com/razzi.s.stefano/YouTube channel youtube.com/channel/UCn85UPNv8vw84-irTR4Db7gg

hi, i have the MSP430 launchpad and am getting the buzzing sound from the audio device, i have not attached the altimeter break out board yet, but have installed the servo wiring. I am getting all LEDS and buzzing when i apply power (using single cell 3.7 lipo ).

i have tried the alternative chip and reprogrammed and even tried redoing the buzzer connection, still getting same buzzing and LEDS.

When i hold the Mode button down on Power up it will go to green LED only but then nothing else will work , servo settings will not adjust etc, until i push the rest button then back to buzzing sound and all LEDS.

any ideas? suggestions? there is really nothing else to check on connections (power is supplied in appropriate polarity in appropriate holes in the board. and like i said i have not installed the altimeter break out board yet, waiting to try and get the launch pad functional first.

ok so i went ahead and added the breakout board and all is good,, im not sure who but someone said it didnt matter if you had the breakout board on the launch pad or not that it would still work, well at least in my case that wasnt the situation, maybe for programming but not for actual use....anyway. looks like this thread isnt even being monitored anymore so it prob would have been two years before i would have gotten any insight

I bought my batteries off of sparkfun, as I had trouble with this as well. (PRT13853 and 13853 for testing). Buying the battery and servo connectors is a royal pain--I ended up with JST 1.25 mm connector kits to line up with what I thought the batteries were, but they were 2.0 mm. I'd just get all the battery wires/connectors from the same place (sparkfun) and really look at the JST connector specs. I used these to attach the servo to the board with a disconnect/replace option.
Once i got it up and running, it's been great with my basic rockets I've been working with the kids (one stage, ring fins and radial deploy).
Any change USWR will make the 3d printed fins project files available? FIns are my nemesis on these things...

I have the MSP430 LaunchPad and the ALTImeter. I am having trouble configuring the altimeter with the servo. I tried to follow the steps but i couldn't even get passed #1. I powered the board, then held MODE while pressing and releasing RESET, and both LED's came on but flashed instead of staying on.